Biased pawl ratcheting wrench

ABSTRACT

A ratchet wrench comprises a handle defining a cavity including a plurality of teeth on an inner periphery thereof, a wheel, a biasing spring ring, and at least one tooth pawl mounted in recesses formed on the outer periphery of the wheel. The wheel is rotatably mounted inside the cavity and the pawls are biased by the spring ring to engage the plurality of teeth on the inner periphery of the cavity when rotated in a first direction, and to slide over the teeth when rotated in a direction opposite the first direction.

CROSS REFERENCE TO RELATED APPLICATION

This application is a non-provisional application claiming priority toU.S. Provisional Application Ser. No. 61/936,134, filed Feb. 5, 2014,and claiming priority to U.S. Provisional Patent Application No.61/890,621, filed Oct. 14, 2013, both entitled “Biased Pawl RatchetingWrench” and the contents of each are both incorporated herein byreference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to ratchet wrenches and moreparticularly to a biased pawl ratcheting wrench.

BACKGROUND OF RELATED ART

Ratchet wrenches are generally known in the art. For example, U.S. Pat.No. 6,530,296 describes a unidirectional ratchet wrench consisting of awrench body, a ratchet, an expanding ring and a plurality of clampingblocks, i.e. pawls. The ratchet is rotatably mounted inside the wrenchbody and has the pawls evenly spaced around the ratchet to engage theinner surface of the wrench body. Two covers are mounted on oppositeopenings of a toothed cavity of the wrench body to enclose the ratchet.

Similarly, U.S. Pat. No. 6,615,693 describes a ratchet including a headand a driving member rotatably received in the head. A plurality ofteeth are defined on the inside surface of the head and a plurality ofnotches are defined on the outer periphery of the driving member. Eachnotch has a pawl received therein which engages the teeth of the insidesurface of the head. A spring ring is mounted to protrusions formed oneach of the pawls and pulls the pawl inward toward the driving member.

Still further, U.S. Pat. No. 6,769,330 describes a ratchet wrenchincluding a driving head having an inner peripheral gear, a wheelrotatably engaged in the driving head and having two openings formed inthe outer peripheral portion. Two pawls are received in the openings ofthe wheel and each has a number of outer teeth for engaging with theinner peripheral gear of the driving head, and each has one end forbeing biased to engage into the end portions of the openings of thewheel by two springs engaging the pawls.

While each of the above-referenced wrenches generally works for theirintended purposes, each of the described wrenches relies upon a wirespring that may be difficult manufacture, to assemble, e.g., may requirespecialized tools, and/or may be prone to failure based upon the sizeand fragility of the spring itself.

As such, there is a recognized need in the art for an improved ratchetwrench assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of an example ratchet wrench inaccordance with the present disclosure.

FIG. 2 is an exploded side elevational view of the example ratchet ofFIG. 1.

FIG. 3 is a perspective view of the assembled example ratchet wrench ofFIG. 1.

FIG. 4 is cross sectional top plan view of the assembled example ratchettaken along line C-C of FIG. 3.

FIG. 5 is a perspective view of an example spring ring for use in theexample ratchet of FIG. 1.

FIG. 6 is a top plan view of the example spring ring of FIG. 5, prior toformation of a plurality of spring leafs.

FIG. 7 is a perspective view of an example wheel for use in the exampleratchet of FIG. 1.

FIG. 8 is a top plan view of the example wheel of FIG. 7.

FIG. 9 is a perspective view of an example pawl for use in the exampleratchet of FIG. 1.

FIG. 10 is a side elevational view of the example pawl of FIG. 9.

FIG. 11 is an enlarged top plan view of an example spring for use withthe example ratchet of FIG. 1.

DETAILED DESCRIPTION

The following description of example methods and example apparatus isnot intended to limit the scope of the description to the precise formor forms detailed herein. Instead the following description is intendedto be illustrative so that others may follow its teachings.

Referring now to FIGS. 1 and 2, an example of a ratchet wrench 10 formedin accordance with the teachings of the present disclosure isillustrated. In this example, the ratchet wrench 10 comprises a handle12, a spring ring 14, a wheel 16, a plurality of pawls 18, and a cap 20.

As illustrated, one end of the handle 12 defines a cavity 22 torotatably hold the spring ring 14, the wheel 16, and the pawls 18 asillustrated in FIG. 1. In this example, one side of the cavity 22 isintegrally formed with a wall or flange 24 to at least partially enclosethe one side of the cavity 22. Meanwhile, the other side of the cavity22 is adapted to removably receive the cap 20, which is configured to bemounted over the cavity 22 and to at least partially enclose the otherside of the cavity 22. In this example, the cap 20 is threaded to engagecorresponding threads formed in the inner wall of the cavity 22. It willbe appreciated by one of ordinary skill in the art that each of theflange 24 and the cap 20 may be integrally or separately formed asdesired, and may be mounted to the handle 12 via any suitable mechanism,including for instance, fasteners, adhesives, solders, etc. Together,the flange 24 and the cap 20, once mounted to the handle 12, cooperateto retain the spring ring 14, the wheel 16, and the pawls 18 within thecavity 22. In addition, the flange 24 and the cap 20 each define anaperture 21 to allow operable access to the elements retained within thecavity 22.

A plurality of teeth 26 are formed longitudinally on an inner peripheryof the cavity 22. In this example, each tooth 26 has a substantiallyequilateral tooth profile. As will be appreciated, however, in someexample, each tooth 26 may include an inclined face and a substantiallyupright face.

As additionally illustrated in FIGS. 7-8, in this example, the wheel 16includes a socket 30 defined in the center and adapted to engage a bolt,nut, fastener, or other similar fitting. In this instance, the examplesocket 30 is defined as a regular polygon, e.g., a hexagon, but it willbe understood that the socket 30 may be any suitable shape and/ordesign. The example wheel 16 also defines arcuate flanges 17 a, 17 b,extending from each side of the wheel 16 and, in this example, sized toextend at least partially through the corresponding aperture defined bythe flange 24 and the cap 20.

At least one pawl recess 32 is longitudinally defined around the outerperiphery of the wheel 16. As will be understood, in the illustratedexample, the wheel 16 includes six evenly dispersed pawl recesses 32around the outer periphery, but any suitable number of pawl recesses 32may be utilized as desired. In addition, the spacing of the pawlrecesses need not be evenly or symmetrically arranged around the outerperiphery, but may be distributed as preferred.

The example pawl recesses 32 are each bordered by an inclined face 37 onone side and a generally upright face 39 that extends outward from theouter periphery of the wheel 16 on the other side. Similar to the teeth26, in his example, all inclined faces 37 and the upright faces 39 ofthe teeth pawl recesses 32 are arranged in the same direction.

At least one pawl 18 is mounted within at least one corresponding pawlrecess 32 in the wheel 16. As illustrated, in this example, each of thesix pawl recesses 32 includes a corresponding pawl 18, and thus theratchet 10 includes six pawls 18 distributed around the wheel 16.

In the example illustrated herein, the six pawls 18 are divided intothree sets of two pawls, and each of the three sets is clockeddifferently by the wheel 16 such that when one set of pawls 18 isengaged with the teeth 26, one of the other sets of pawls 18 is onlypartially engaged (e.g., half engaged) and the remaining set of pawls isdisengaged. By clocking the pawls differently a coarser tooth patterncan be used while maintaining a fine tooth pattern action. It will beappreciated that the arrangement and number of sets, and the variousclocking patterns associated with the pawls may vary with differingdesign arrangements.

As best seen in FIGS. 9 and 10, each of the example pawls 18 includes atoothed face 40 facing outward (e.g., away from the wheel 16 whenassembled) and a substantially smooth face 42 facing inward (e.g.,towards the wheel 16 when assembled). In this example, the toothed face40 includes at least one tooth 44, such as for example a plurality ofteeth 44 to engage the teeth 26 formed on the inner periphery of thecavity 22 when both the pawls 18 and the wheel 16 are assembled withinthe cavity 22. In the illustrated example, each pawl includes five teeth44 formed on the pawl 18, and a sixth tooth 44 a formed on one end 18 aof the pawl 18. It will be appreciated by one of ordinary skill in theart that the number and/or shape of the teeth 44, 44 a may vary asdesired, and while each of the teeth 44 may be generally similar, if notidentical, in shape, the shape and/or position of the teeth 44 may varyto provide different effects, such as for instance, various clockingmodes as appropriate.

In this example, as best illustrated in FIG. 10, the five teeth 44 aregenerally uniform in appearance and include a substantially triangulartooth profile. The sixth tooth 44 a meanwhile includes a slightly morerounded tooth profile, which as will be described in detail herein, maybetter assist in allowing the pawl 18 to move relative to the innerperiphery of the cavity 22 when the wheel 16 is rotated in the correctdirection. In addition, to further assist the pawl 18 in movementrelative to the inner periphery of the cavity 22, the smooth face 42near the end 18 a of the pawl 18 may include a cammed surface 50 forengagement with the corresponding inclined face 37 of the pawl recess32. An opposite end 18 b includes a generally flat surface. It will beunderstood, however, that the number, arrangement, and/or shape of anyof the teeth 44 as well as the overall shape of the faces of the pawl 18may vary as desired.

As best illustrated in FIG. 5, the example spring ring 14 includes agenerally planar surface 60, and at least one resilient biasing leaf 62extending from the planar surface 60. In this example, the spring ring14 includes six leafs 62 corresponding to the number of pawl recesses 32and pawls 18. The planar surface 60 of the spring ring 14 is sized to bemounted inside the cavity 22 and abut one of the flange 24 or the cap20. The spring ring 14 further defines an aperture 64 substantiallycorresponding to the size of the aperture 21.

When assembled, the leaf 62 of the spring ring 14 longitudinally extendsinto the corresponding pawl recess 32 between the upright face 39 of thepawl recess 32 and the flat surface of the end 18 b of the pawl 18. Inthis manner the spring ring 14 biases the pawl 18 away from the uprightface 39 of the pawl recess, and towards the teeth 26 along the innerperiphery of the cavity 22, thereby engaging the teeth 44 on the pawl 18with the teeth 26 in the cavity 22.

As illustrated in FIG. 6, in one example the spring ring 14 ismanufactured from a single piece of resilient material through anysuitable manufacturing technique, including for instance, stamping, etc.As shown, the leafs 62 may be cut and/or otherwise separated from theplanar surface 60 and resiliently bent away from the surface 60 to formthe resilient biasing leaf 62. The relative ease of manufacturing andthe relative ease of assembling the components of the ratchet 10 willtherefore be appreciated.

With reference to the cross sectional illustration of FIG. 4, inoperation, the assembled ratchet wrench 10, and more particularly thesocket 30 is placed over a nut or other suitable element and is engagedinside the socket 30. In the orientation illustrated in FIG. 4, thehandle 12 is rotated in the direction of the arrow A (e.g.,counter-clockwise) to make the teeth 44 of the pawl 18 engage the teeth26 of the cavity 22. Specifically, upon rotation of the handle 12 in thedirection of the arrow A, the pawl 18, under a biasing force created bythe leaf 62 is forced towards the teeth 26 and as rotation continues, isthus urged by the engagement of the teeth 26 and the pawl teeth 44against the bias towards the upright face 39 of the wheel 16. The wheel16 is therefore pushed by and rotates with handle thereby rotating thenut or other element engaged inside the socket 30.

Still referring to FIG. 4, when the handle is rotated in the directionof the arrow B (e.g., counter-clockwise), the teeth 44 of the pawl 18move along the teeth 26, sliding over the teeth 26 (i.e., ratcheting).In this instance, the wheel 16 does not rotate with the handle 12, andthe ratchet wrench 10 does not rotate the nut or other element engagedinside the socket. To reverse the direction of the arrows A and B, thewrench 10 need only be turned over.

As can be seen in the example of FIG. 4, the six pawls 18 are dividedinto three sets each of the sets having two pawls 18 respectively. Thesample pawl sets are each clocked differently by the wheel 16 such thatwhen one set of pawls is engaged with the teeth 26, one of the othersets of pawls is only partially engaged (e.g., half engaged) and theremaining set of pawls is disengaged.

Referring now to FIG. 11, there is illustrated another example spring14′ for use in the example wrench 10. The spring 14′ may be used as analternative to the spring ring 14 or may be used in addition to thespring ring 14 as desired. In this example, the spring 14′ includes acoil spring located within at least one of the pawl recesses and betweenthe upright face 39 of the wheel 16 and the corresponding flat surfaceof the end 18 b of the pawl 18. In this manner the spring 14′ similarlybiases the pawl 18 away from the upright face 39 of the pawl recess, andtowards the teeth 26 along the inner periphery of the cavity 22, therebyengaging the teeth 44 on the pawl 18 with the teeth 26 in the cavity 22.As will be appreciated by one of ordinary skill in the art the spring14′ and/or the spring ring 14 as disclosed herein may be any suitablespring for locating between the pawl and the upright face of the innerwheel and/or for biasing the pawl 18 into contact with the teeth 26 ofthe cavity 22. For example, in alternative and/or in addition to thesprings already disclosed, the bias may be provided by any resilientelement included a resilient material, a torsion spring, a tensionspring, a flat spring, leaf spring, helical spring, volute spring, orany other suitable biasing member.

Although certain example methods and apparatus have been describedherein, the scope of coverage of this patent is not limited thereto. Onthe contrary, this patent covers all methods, apparatus, and articles ofmanufacture fairly falling within the scope of the appended claimseither literally or under the doctrine of equivalents.

We claim:
 1. A ratchet wrench comprising: a handle having an enddefining a cavity and a plurality of teeth formed circumferentially onan inner periphery of the cavity; a wheel rotatably mounted in thecavity of the handle and comprising: a socket adapted to engage a nut orother suitable element; and a pawl recess defined around an outerperiphery of the wheel, the pawl recess being bordered by an inclinedface on one side and a generally upright face on the other, bothextending from the outer periphery of the wheel; a pawl received in thepawl recess, the pawl having at least one tooth wherein the at least onetooth is provided to selectively engage with a corresponding one or moreof the plurality of teeth formed on the inner periphery of the cavity;and a spring member mounted in the cavity of the handle and positionedwithin the pawl recess entirely between the upright face of the pawlrecess and a surface of the pawl that generally faces towards theupright face of the pawl recess, wherein the spring member, withoutrequiring movement of the wheel, provides a biasing force against thesurface of the pawl in a direction that is away from the upright face ofthe pawl recess and substantially towards the inclined face of the pawlrecess to urge the pawl into the inclined face of the pawl recess and,thereby, into contact with the inner periphery of the cavity.
 2. Theratchet wrench as recited in claim 1, wherein the cavity comprises anintegrally formed flange to at least partially enclose one side of thecavity.
 3. The ratchet wrench as recited in claim 1, wherein the cavityis configured to receive a removable cap to at least partially encloseone side of the cavity.
 4. The ratchet wrench as recited in claim 3,wherein the cavity is threaded to receive corresponding threads formedon the removable cap.
 5. The ratchet wrench as recited in claim 1,wherein the spring member is a leaf spring.
 6. The ratchet wrench asrecited in claim 5, further comprising a ring member having a generallyplanar surface and wherein the leaf spring comprises a resilient elementattached at one end to the ring member at an angle relative to thegenerally planar surface.
 7. The ratchet wrench as recited in claim 6,wherein the cavity comprises an integrally formed flange to at leastpartially enclose one side of the cavity and the generally planarsurface of the ring member is disposed intermediate the flange and thewheel.
 8. The ratchet wrench as recited in claim 7, wherein the cavityis configured to receive a removable cap to at least partially encloseone side of the cavity and the generally planar surface of the ringmember is disposed intermediate the flange and the wheel.
 9. The ratchetwrench as defined in claim 1, wherein the spring member is a coilspring.
 10. The ratchet wrench as defined in claim 1, wherein the pawlincludes a cammed surface for abutting the inclined face defining thepawl recess.
 11. The ratchet wrench comprising: a handle having an enddefining a cavity and a plurality of teeth formed on an inner peripheryof the cavity; a wheel rotatably mounted in the cavity of the handle andcomprising: a socket; and a plurality of pawl recesses defined around anouter periphery of the wheel, each of the pawl recesses being borderedby an inclined face on one side and a generally upright face bothextending from the outer periphery of the wheel; a pawl received in eachof the pawl recesses, each of the pawls having at least one toothwherein the at least one tooth is provided to selectively engage with acorresponding one or more of the plurality of teeth formed on the innerperiphery of the cavity, wherein the at least one tooth of at least twoof the plurality of pawls will be engaged with a corresponding one ormore of the plurality of teeth formed on the inner periphery of thecavity at different rotational positions of the wheel is relative to theinner periphery of the cavity; and a plurality of spring members mountedin the cavity of the handle and each being positioned within acorresponding one of the plurality of pawl recesses entirely between theupright face of the corresponding one of the plurality of pawl recessesand a surface of a one of the plurality of pawls disposed within thecorresponding one of the pawl recesses that generally faces towards theupright surface of the corresponding one of the plurality of pawlrecesses, wherein each of the plurality of spring members, withoutrequiring movement of the wheel, provides a biasing force against thesurface of a corresponding one of the plurality of pawls in a directionthat is away from the upright face of the corresponding one of theplurality of pawl recesses and substantially towards the inclined faceof the corresponding one the plurality of pawl recesses to urge each ofthe plurality of pawls into the inclined face of the corresponding oneof the plurality of pawl recesses and, thereby, into contact with theinner periphery of the cavity.
 12. The ratchet wrench as recited inclaim 11, wherein the plurality of pawl recesses are evenly distributedabout the outer periphery of the wheel.
 13. The ratchet wrench asrecited in claim 11, wherein at least two of the plurality of pawlrecesses are distributed about the outer periphery of the wheel onehundred and eighty degrees relative to one another.
 14. The ratchetwrench as recited in claim 11, wherein the at least one tooth on atleast two of the plurality of pawls are located in different locationson the corresponding pawl.
 15. The ratchet wrench as recited in claim11, wherein each of the plurality of spring members is a leaf spring.16. The ratchet wrench as recited in claim 15, further comprising a ringmember having a generally planar surface and wherein each of theplurality of leaf springs comprises a resilient element attached at oneend to the ring member at an angle relative to the generally planarsurface.
 17. The ratchet wrench as recited in claim 16, wherein thecavity comprises an integrally formed flange to at least partiallyenclose one side of the cavity and the generally planar surface of thespring element is disposed intermediate the flange and the wheel. 18.The ratchet wrench as recited in claim 17, wherein the cavity isconfigured to receive a removable cap to at least partially enclose oneside of the cavity and the generally planar surface of the ring elementis disposed intermediate the flange and the wheel.
 19. The ratchetwrench as defined in claim 11, wherein each of the plurality of springmembers is a coil spring.
 20. The ratchet wrench as defined in claim 11,wherein each of the plurality of pawls includes a cammed surface forabutting the inclined face defining the pawl recess of the correspondingone of the plurality of pawl recesses.